Abstract

Breeding dispersal, defined as the net movement between successive breeding sites, remains a poorly understood and seldom reported phenomenon in mammals, despite its importance for population dynamics and genetics. In large herbivores, females may be more mobile during the breeding season, undertaking short-term trips (excursions) outside their normal home range. If fertilisation occurs, leading to gene flow of the male genome, this behaviour could be considered a form of breeding dispersal from a genetic point of view. Here, we investigated ranging behaviour of 235 adult roe deer using intensive GPS monitoring in six populations across Europe within the EURODEER initiative. We show that excursions are common from June to August among females, with 41.8 % (vs. 18.1 % of males) making at least one excursion. Most individuals performed only one excursion per season and departure dates for females were concentrated in time, centred on the rutting period, suggesting a link with reproduction. The distance females travelled during excursions was significantly greater than the site-specific average diameter of a male home range, while travel speed decreased once they progressed beyond this diameter, indicating search behaviour or interaction with other male(s) outside the resident male’s territory. Because adults are normally highly sedentary, the potential for mating with relatives is substantial; hence, we conclude that rut excursions could be an alternative tactic enabling females to avoid mating with a closely related male. To understand better the ultimate drivers at play, it will be crucial to explore the genetic causes and consequences of this behaviour.

Keywords

Mate choice Inbreeding avoidance GPS telemetry Rut excursion Ungulate

Communicated by Göran C. Ericsson.

Electronic supplementary material

The online version of this article (doi:10.1007/s00442-014-3021-8) contains supplementary material, which is available to authorized users.

Notes

Acknowledgments

This paper was conceived and written within the EURODEER collaborative project (paper 3 of the EURODEER series; www.eurodeer.org). Co-authors are grateful to all members for their support for the initiative. We also thank two anonymous referees and the handling editor for constructive comments on an earlier version of this paper. The EURODEER spatial database is hosted by the Edmund Mach Foundation. GPS data collection of the Edmund Mach Foundation was supported by the Autonomous Province of Trento under Grant N. 3479 to F. Cagnacci (BECOCERWI–Behavioural Ecology of Cervids in Relation to Wildlife Infections). F. Cagnacci thanks the Wildlife and Forest Service of the Autonomous Province of Trento and the Hunting Association of Trento Province (A.C.T.) for support and help during captures. Financial support for GPS data collection in the Bavarian Forest was provided by the EU-programme INTERREG IV (EFRE Ziel 3) and the Bavarian Forest National Park Administration. The Swedish study was supported by grants from the private foundation of “Marie Claire Cronstedts Minne”, The Swedish Environmental Protection Agency and The Swedish Association for Hunting and Wildlife Management. M. Hewison and N. Morellet would like to thank the local hunting associations, the Fédération Départementale des Chasseurs de la Haute Garonne, as well as numerous co-workers and volunteers for their assistance and, in particular, B. Cargnelutti, J.M. Angibault, B. Lourtet, D. Picot and J. Merlet. The France South study was partly funded by the INDHET ANR grant (ANR-12-BSV7-0023-02). C. Vanpé and L. Debeffe were supported by the PATCH RPDOC ANR project (ANR-12-PDOC-0017-01) attributed to CV from the French National Research Agency (PATCH project). The Norwegian study was financed by the Research Council of Norway, the Directorate for Nature Management, and the county governor’s office in Buskerud county. The authors declare that they have no conflict of interest.

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